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Change loop structure for sample synthesizing. Gives a nice speedup on both coldfire and arm targets.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15036 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Nils Wallménius 2007-10-08 19:28:41 +00:00
parent d712e252fe
commit f619f81676
3 changed files with 64 additions and 76 deletions
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55
apps/plugins/midi/synth.h
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@ -17,61 +17,8 @@
*
****************************************************************************/
int initSynth(struct MIDIfile * mf, char * filename, char * drumConfig);
int synthVoice(struct SynthObject * so);
void setPoint(struct SynthObject * so, int pt);
static inline void synthSample(int * mixL, int * mixR)
{
int i;
register int dL=0;
register int dR=0;
register int sample = 0;
register struct SynthObject *voicept=voices;
for(i=MAX_VOICES/2; i > 0; i--)
{
if(voicept->isUsed==1)
{
sample = synthVoice(voicept);
dL += sample;
sample *= chPan[voicept->ch];
dR += sample;
}
voicept++;
if(voicept->isUsed==1)
{
sample = synthVoice(voicept);
dL += sample;
sample *= chPan[voicept->ch];
dR += sample;
}
voicept++;
}
/* if MAX_VOICES is not even we do this to get the last voice */
#if MAX_VOICES%2
if (MAX_VOICES%2)
{
if(voicept->isUsed==1)
{
sample = synthVoice(voicept);
dL += sample;
sample *= chPan[voicept->ch];
dR += sample;
}
}
#endif
dL = (dL << 7) - dR;
*mixL=dL >> 7;
*mixR=dR >> 7;
/* TODO: Automatic Gain Control, anyone? */
/* Or, should this be implemented on the DSP's output volume instead? */
return; /* No more ghetto lowpass filter. Linear interpolation works well. */
}
void synthSamples(int32_t *buf_ptr, unsigned int num_samples);
static inline struct Event * getEvent(struct Track * tr, int evNum)
{